And if you would just pay attention to the cause of our loss of time, you would discover that the greatest part of our life slips away while we are doing evil, or doing nothing at all - practically our entire lives are wasted doing something other than what we should be doing.
- Epistle 1
There was an eternity before we were born and there will be an eternity after we die. Whether we live a hundred years longer or just one more day makes no difference. The extra years, in the grand scheme of things, is less than a drop in a giant bucket. How we live our lives is what matters. One of Plato's most famous lines, which he placed in the mouth of Socrates, was: "It is not living, but living well which is important." Plato was not a Stoic, but his well known saying is very much a stoic sentiment. Our own Seneca the Younger wrote: "It is not how long you live that matters, but how nobly."
The good news is that nothing and nobody can prevent us from living nobly (or, if necessary, dying nobly). A virtuous life is always within our grasp, whether that life be for a few hours more or for many decades more.
The bad news is that - although most of us have more than a few hours to live and many of us still have many decades left - most of us will waste that time just as we have always squandered our time before this moment. We waste our time when we forget that Virtue is the only good and Vice is the only evil, and that our character is the only thing that truly belongs to us.
Thus, the man that lives for only one day more but lives that day virtuously has lived longer than the man who lives another sixty years but lives viciously.